This invention relates to a programmable cartridge fed ambulatory infusion pump powered by a DC electric motor.
It is an object of this invention to provide a compact, lightweight infusion pump which may be used for ambulatory patients. It is a further object of this invention to provide a pump which can be conveniently used with fluid source cartridges.
There has been a demonstrated need for pumps which can intravenously administer a plurality of drug solutions. For example, multiple drug chemotherapy treatments have been used to treat diseases such as cancer. Many of the drugs used in chemotherapy and other therapies cannot be mixed together prior to an infusion. Some of these drugs react to neutralize one another. Other drugs react to form precipitates which may block the catheter tube or possibly cause an embolism in the patient. Pumps have been developed which can concurrently pump a plurality of fluids through a multilumen catheter into a patient. The multilumen catheter keeps the drugs separate until they reach the bloodstream. For example, in U.S. Pat. No. 4,741,736 (Brown), a pump is disclosed which uses a roller to push fluid out of a plurality of compartments in an infusion pump. The different fluids in each of the compartments are pumped out at the same time by the action of the single roller.
In infusion pump patent, U.S. Pat. No. 4,666,430 (Brown and Tai), a multiple syringe pump is disclosed in which a canister of compressed gas serves as the power source for pumping fluid out of a syringe. All of the syringes are controlled by the same canister of gas and variation in the pumping rate of a syringe is controlled by valves on the outlets of the syringes.
It is an object of the present invention to provide in a single ambulatory housing, separately and accurately controlled pumping mechanisms for each of a plurality of fluid sources. It is typical in infusion pumps where accurate infusion rates are desired to use a stepper motor. However, in providing an ambulatory pump, it is desirable to use smaller, lighter motors such as the dc electric motors of the present invention. A further object of the present invention is to provide controlled infusion rates with dc electric motors.
In order to deliver fluid at a precisely determined rate through a linear peristaltic pump, the pump value must be accurately positioned with respect to the fluid delivery tube. Any warping of the cartridge or any mispositioning of the pump may permit a leak when a pump valve is depressed against the tube. It is an object of this invention to provide a cartridge and tube mount which accurately position a tube within an infusion pump. It is desirable that accuracy be obtained using low cost plastic pieces.